With the improvement of technology, lot types of wind turbine system such as small wind power systems are widely used in general families for obtaining power through wind power.
In general, the rotational speed of a wind turbine of the small wind power system is varied with the wind speed of outer wind. The ratio of the rotational speed to the wind speed depends on the combination of the torque force of a power generator and the blades of the wind turbine, so that the rotational speeds of different designed wind turbines will not be the same. When the wind speed of outer wind is raised, the rotational speed of the wind turbine is also raised. However, the noise of the operation of the blades and the low-frequency vibration of the hub is too loud, and the environment is affected. In addition, compared with the solar power system, the outer wind is irregularly varied, which means that the noise of the wind turbine system is also irregularly generated. To solve this problem, the conventional wind turbine system is usually configured with a fan-stopping device.
The common fan-stopping devices can be classified into three types. The first one is a short circuit fan-stopping device used for making the three-phase circuit of the power generator of the wind turbine a short circuit. The second one is a physical break used for stopping the fan through mechanical means and elements. The third one is configured with a power converter for users to be manual operated as a short circuit. All the three types of the fan-stopping devices are manual operated by technicians, so that the technicians have to move close to the wind turbine to maintain or repair when the high-dB noise is generated. It exists some safety problems.
An example of the conventional wind turbine control system is described in U.S. Pat. No. 8,433,425 B2. Please refer to FIG. 1. FIG. 1 schematically illustrates the system configuration of the conventional wind turbine control system. As shown in FIG. 1 and described in the prior art, the wind turbine control system is provided for users to input control rules, and a supervisory control and data acquisition system is provided as the computing input of a rule engine 408. In practical application, because the user is not familiar with the wind turbine control system, the rule establishment is incomplete, the construction time is too long to complete the control mechanism, and hence the safety concerns are arisen.
Moreover, the ambition of people to install the small wind power system is usually low due to the noise and the safety problem, and the cost of an automatic control system is too high to be applied in general families, so that the family used small wind power system is still manually stopped and maintained during emergency.
There is a need of providing a wind turbine control system and a control method thereof to avoid the dangers and obviate the drawbacks encountered from the prior art.